7. Project Summary Lung cancer is the leading cause of cancer death in the United States. The National Lung Screening Trial (NSLT) recently reported that low-dose CT screening reduced cancer mortality among at-risk populations. Guidelines support screening for patients meeting NSLT eligibility criteria, but note the importance of ensuring that screened patients have access to high-volume, high-quality screening and treatment centers. Furthermore, the absolute benefit of screening is small, and must be weighed against potential downstream harms, including complications from diagnostic testing. Consequently, guidelines also encourage clinicians to engage patients in shared decision-making (SDM), helping them to clarify their values for the potential outcomes of screening and to use screening as a teachable moment for addressing cessation. One way to accomplish this is by using decision support tools (decision aids) that can accommodate low-literacy, non- English speakers, and be culturally appropriate. Minority populations, who were not well represented in NLST, are less likely than non-Hispanic whites to be current with a variety of cancer screening tests, less likely to present with local stage cancer, and less likely to undergo aggressive curative treatment. These disparities have been attributed to socioeconomic factors, language barriers, limited health literacy, and to specific knowledge, attitudes, and beliefs about screening and treatment. Understanding how these factors could impact lung cancer screening programs and smoking cessation efforts is important for developing patient decision aids and provider decision support tools and for guiding patient-provider discussions to enhance shared decision making. The objective of this project is to conduct formative research identifying patient and provider barriers and facilitators to engaging in shared decision making for lung cancer screening and smoking cessation among underserved minority populations. We will utilize participatory research methods to conduct the qualitative research, including interviews and focus groups, to identify patient and provider factors relevant to decision making around low-dose computer tomography (LDCT) screening and smoking cessation. These results will inform development of lung cancer screening and smoking cessation decision-support tools. We will conduct the research within a practice-based research network and an academic lung nodule clinic that provides care to underserved populations who can access a high-quality academic cancer diagnostic and treatment center. Subjects will include current or former smokers found to have lung nodules on CT imaging, at-risk current or former smokers, and primary care providers. Findings from this research could ultimately lead to reducing the burden of lung cancer in underserved populations.